Most Delta V SSTO (no Ions)

[Redshift OTF]

Hmmm, it's been a while since I last played KSP and my first thought was to try and build a really efficient SSTO. I think I did really well with the effort but I want to know who can do more because whatever I do someone else can usually do better!

Rules:

Build an SSTO that has the most Delta V when in Orbit.

1) Can be a space plane SSTO that takes off from the runway or a launch pad SSTO. I will consider them separate categories though.

2) Nothing can blow up or become attached from the SSTO. What goes up must come down in one piece.

3) Must carry a Kerbal in a cockpit. No chairs in service bays.

4) Must reach aprox 100km circular orbit.

5) No Ion engines! They're nice but I want something semi-practical.

6) No part mods except MechJeb, Kerbal Engineer etc.

7) No cheat menu options except part clipping if you really need it.

8) Post a screen shot / video / craft file / whatever as proof.

This is my effort. I hope it can be beaten! Craft file can be provided if anyone wants it.

Spoiler

6584 Delta V remaining. It's an unusual design but that's to get the drag as low as possible. It could go higher if I had some way of cooling the cockpit down as this limits the Rapier speed run to 1500 m/s.

Don't worry if your entry is not the highest. I still want to see designs that are cool looking and/or practical.

Edited November 18, 2016 by Redshift OTF

[Nefrums]

That is an inpressive amount of dV.

You should be able to go 1650 in airbreathing mode. I suspect that the canards transfer heat to the cockpit.

[Eidahlil]

Sounds like a great (aka my kind of) challenge.

9 hours ago, Redshift OTF said:

6584 Delta V remaining

I have some bad news, and some good news

The bad news is that the dev version of MechJeb (or KER) doesn't think the NERV can get fuel from radially attached tanks (spoiler: it can in 1.2). It's not a major difference in your design, but I'm guessing you do have some LF in those BigS wing strakes.

The good news is that for an SSTO it's easy to calculate manually using Tsiolkovsky rocket equation. Which in the case of NERV is dV = 800 * 9.80665 * ln( mass / ( mass - 0.005 * LF )). So in your spaceplane case (the third screenshot) the dV would be 7056 = 800 * 9.80665 * ln( 82.333 / ( 82.333 - 0.005 * 9768 )).

The good for you and bad for me news is that my SSTO has only 6618  (and is a very clear example of the above problem). I'll be back with another design though.

[Redshift OTF]

9 hours ago, Nefrums said:

That is an inpressive amount of dV.

You should be able to go 1650 in airbreathing mode. I suspect that the canards transfer heat to the cockpit.

O RLY? Thanks, I will test that as I should be able to improve my flight profile if I can take more heat!

5 hours ago, Eidahlil said:

Sounds like a great (aka my kind of) challenge.

I have some bad news, and some good news

The bad news is that the dev version of MechJeb (or KER) doesn't think the NERV can get fuel from radially attached tanks (spoiler: it can in 1.2). It's not a major difference in your design, but I'm guessing you do have some LF in those BigS wing strakes.

The good news is that for an SSTO it's easy to calculate manually using Tsiolkovsky rocket equation. Which in the case of NERV is dV = 800 * 9.80665 * ln( mass / ( mass - 0.005 * LF )). So in your spaceplane case (the third screenshot) the dV would be 7056 = 800 * 9.80665 * ln( 82.333 / ( 82.333 - 0.005 * 9768 )).

The good for you and bad for me news is that my SSTO has only 6618  (and is a very clear example of the above problem). I'll be back with another design though.

Interesting! I just did a quick test and you are correct, it ignores fuel in the strafe wings. I guess 7056 is the new target to beat. Thanks for doing the maths and next time I will pump fuel out of the side wings to allow Mechjeb to give the correct figure.

[Foxster]

1 hour ago, Redshift OTF said:

O RLY? Thanks, I will test that as I should be able to improve my flight profile if I can take more heat!

Interesting! I just did a quick test and you are correct, it ignores fuel in the strafe wings. I guess 7056 is the new target to beat. Thanks for doing the maths and next time I will pump fuel out of the side wings to allow Mechjeb to give the correct figure.

Umm, if you are using KSP1.2 then MJ should take account of the fuel in the wings for the dV - at least it does in the latest dev version of MJ. 

This is a Mun return SSTO I knocked together a little while ago. Might not be the biggest but it has pretty good dV for the size...

 

Edited November 19, 2016 by Foxster

[Redshift OTF]

36 minutes ago, Foxster said:

Umm, if you are using KSP1.2 then MJ should take account of the fuel in the wings for the dV - at least it does in the latest dev version of MJ. 

Thank you! I was using an older version. I have upgraded now and have an improved SSTO to reveal:

Spoiler

7419 Delta V. This one only just got to orbit though. I got up to 60km but it fell back down to 35km while firing the LV-Ns. Luckily my orbital speed was almost 2400m/s so the plane started rising again. Also lucky the plane is designed for ultra low drag by careful selection of parts so it survived this drop in altitude. It goes transonic pretty easily so I feel confident I can put more oxidiser in it to make a better version.

 

[Foxster]

Those quad adapter are incredibly draggy. I think you might find a few more dV if you could find a way around them. Like four radially attached Advanced Nose Cone - Type A. 

17 hours ago, Redshift OTF said:

It could go higher if I had some way of cooling the cockpit down as this limits the Rapier speed run to 1500 m/s.

You could try swapping out for Mk1 capsule with a Communotron 16 on the front like the craft I posted above. I doubt you need that shockcone intake. 

[Redshift OTF]

7 minutes ago, Foxster said:

Those quad adapter are incredibly draggy. I think you might find a few more dV if you could find a way around them. Like four radially attached Advanced Nose Cone - Type A. 

They are very draggy but most of the rest of the craft has low drag so I get better returns as I increase the size of the craft. I like your idea though although I thought anything added radially to a craft counts as a side pod that increases drag more? Is this no longer the case? If not then I can go a lot further with this design line!

[Foxster]

7 minutes ago, Redshift OTF said:

They are very draggy but most of the rest of the craft has low drag so I get better returns as I increase the size of the craft. I like your idea though although I thought anything added radially to a craft counts as a side pod that increases drag more? Is this no longer the case? If not then I can go a lot further with this design line!

It's a balancing act - like most things. You'd need to turn on the aero stats and compare the two ways. You would be putting the nosecones on the front of your 8 stacks so aren't adding more stacks. 

[Nefrums]

I made a try  with 8 rapiers and one nerv:

http://imgur.com/a/QF2OA

Got 8456 m/s dV left in orbit 

[Foxster]

Comparing these two...

With the first one, the nosecones have a max drag (launching vertically) of 4 x 1.62. 

On the craft with the quad adapter, the max drag of the adapter is 82. 

Also, the drag of the tanks and engines is less on the first craft. 

So, clearly radially attached nose cones are waaaay less draggy. Though the mass is slightly higher. You also want a nosecone of some type on the bottom of the central tank. 

[Redshift OTF]

12 minutes ago, Nefrums said:

I made a try  with 8 rapiers and one nerv:

http://imgur.com/a/QF2OA

Got 8456 m/s dV left in orbit 

Woah. Consider my entry wrecked! Lol. Yeah it looks like side pods are the way to go. And avoiding Mk2 parts as they are very draggy.

[Nefrums]

Yes even the Mk2 bicoupler is very draggy.

 

 

[Redshift OTF]

7 minutes ago, Foxster said:

Comparing these two...

With the first one, the nosecones have a max drag (launching vertically) of 4 x 1.62. 

On the craft with the quad adapter, the max drag of the adapter is 82. 

Also, the drag of the tanks and engines is less on the first craft. 

So, clearly radially attached nose cones are waaaay less draggy. Though the mass is slightly higher. You also want a nosecone of some type on the bottom of the central tank. 

 

1 minute ago, Nefrums said:

Yes even the Mk2 bicoupler is very draggy.

 

 

Consider myself educated on this matter. I will have to ditch couplers and try this design although it might be a bit tricky mounting a lot of these. I'm slight wary about using just 1 LV-N as I was hoping to make an Eeloo SSTO and I'm worried that 1 LV-N won't have enough TWR to land on it or even to do the interplanetary transfers efficiently enough. A challenge is a challenge though!

[Nefrums]

You would need 3 nervs to land a ship this size on Eeloo,  2 might be possible as you would burn most of the fuel to get there.

A SSTEeloo would need around 6km/s dVif you do direct transfers, with gravity assists you could probably do it for half that.

 

 

Edited November 19, 2016 by Nefrums

[Redshift OTF]

5 minutes ago, Nefrums said:

You would need 3 nervs to land a ship this size on Eeloo,  2 might be possible as you would burn most of the fuel to get there.

A SSTEeloo would need around 6km/s dVif you do direct transfers, with gravity assists you could probably do it for half that.

 

 

Yeah Mark Thrimm did it in 1.0.5 and needed 6500 Delta V with gravity assists. It definitely influenced me to make something with more Delta V to make the voyage less painful. And he didn't have a cockpit. I wonder if a non-Ion Moho SSTO is now possible?

 

Edited November 19, 2016 by Redshift OTF

[Redshift OTF]

Managed to break my record with this badboy:

8056 Delta V. The TWR of the LV-N's is abysmal but I guess it's enough to go to Eeloo and back.

I also discovered something new. If you replace quad-couplers with nose cones attached to another object, say a small fuel tank it doesn't really help with drag. What happens is the drag of the nose cones and everything attached behind them is transferred to the object they are attached to and the object becomes incredibly draggy even if it is a low drag object. I then had a brain wave and knowing that wing strafes have pretty low drag I placed 2 of them behind the cockpit and attached the nose cones to that. In this case they didn't transfer their drag to the wing strafes and my overall drag was a lot less.

[NightshineRecorralis]

This is an SSTO that can go to the Mun and back with a full orange tank, Not quite sure about dV, since KER seems confused about the total amount of LF and which engines I'm using. If I swap the orange tank to all LF, this easily becomes interplanetary. LF can be clearly seen in the top right.

Mun insertion

Mun landing

Kerbin return

[Redshift OTF]

@NightshineRecorralis You can get an Orange tank to the Mun? That is most impressive! Maybe if you replaced the cargo bay section with a fuel tank you could get some monster Delta V in orbit.

[NightshineRecorralis]

7 hours ago, Redshift OTF said:

@NightshineRecorralis You can get an Orange tank to the Mun? That is most impressive! Maybe if you replaced the cargo bay section with a fuel tank you could get some monster Delta V in orbit.

I will certainly try, but what good is an SSTO that can just get somewhere? That was the point of the cargo bay, to resupply future mun missions and conduct rescues if needed. I'll post results when I get on my proper gaming pc instead of the brick I'm using right now.

[Redshift OTF]

Haha, thanks! Getting an SSTO to Eeloo or, heaven forbid, Moho is quite an achievement to be fair. Having perfected my design I have an SSTO that has 7243 Delta V but also a TWR of 0.20 in Kerbin orbit so would actually be useful for landing on Eeloo. So they have their uses. Although the challenge is just just have the most Delta V in orbit which is possible with having a very low TWR of LV-Ns and a load of Rapiers.

[NightshineRecorralis]

On 11/20/2016 at 4:07 PM, Redshift OTF said:

Haha, thanks! Getting an SSTO to Eeloo or, heaven forbid, Moho is quite an achievement to be fair. Having perfected my design I have an SSTO that has 7243 Delta V but also a TWR of 0.20 in Kerbin orbit so would actually be useful for landing on Eeloo. So they have their uses. Although the challenge is just just have the most Delta V in orbit which is possible with having a very low TWR of LV-Ns and a load of Rapiers.

I'll get to it over Thanksgiving, I haven't forgotten about this

[NightshineRecorralis]

@Redshift OTFI'm beginning the challenge now, looks good so far, but it appears that KER is confused again, insisting that I have less than 900m/s when I clearly have more

Turns out I actually had a bit of excess OX, with that in mind, I calculated the Δv to be 6685m/s=800* 9.80665*ln(258.186/(258.186-0.005*29615)) I don't know what the Δv is without the Oxidizer, though

Here's the album for the flight profile and proof: http://imgur.com/a/3eA7t

Download here: https://kerbalx.com/NightshineRecorralis/Wyvern-IP

Yeah, doing this at less than 10fps was a challenge ^^ Took 20min in game, but really took like an hour in real time.

 

Edited November 22, 2016 by NightshineRecorralis

[Redshift OTF]

18 minutes ago, NightshineRecorralis said:

@Redshift OTFI'm beginning the challenge now, looks good so far, but it appears that KER is confused again, insisting that I have less than 900m/s when I clearly have more

 

Will edit for pics and proof

Nice one! I'm looking forward to it. You could always use the latest dev version of Mechjeb as that is showing Delta V correctly now.

[NightshineRecorralis]

6 minutes ago, Redshift OTF said:

Nice one! I'm looking forward to it. You could always use the latest dev version of Mechjeb as that is showing Delta V correctly now.

Does it show the delta v of just LF without ox?